The Suez conflict provided lessons for British strategy and defence policy — beyond the long list of things not to do:
Since the early 1950s, the role of the Royal Navy and even of sea power more broadly had come under concerted attack in Whitehall. The Air Ministry pushed hard for a narrow focus on the early, nuclear stage of a total war with the USSR – for which, as it happened, the RAF’s cherished medium bomber force was well suited. This approach left little room for naval power; why seek to defend sea communications when the war would be settled quickly, by nuclear weapons? Some senior politicians and civil servants were convinced of the strategic logic of this case, while others went along with an approach that appeared to offer significant savings in defence spending. The Admiralty put up a spirited counter-case arguing that defence policy could not plan only for total war, let alone for only one form that such a war might take. Conventional forces, it insisted, including naval power, were an indispensable part of the deterrent to war; they would be essential to fighting any war if Britain was to survive; and they were vital for waging the cold war, which was bound to continue and even intensify as total war became less likely. The strategic logic of the Admiralty case was compelling but the financial implications were unpalatable; the Navy held on but only just and the assaults kept coming. Suez provided a much needed reality check.
First, it was a reminder that while deterring or fighting total war with the Soviet Union was bound to be the main focus for policy, it was not the only game in town. Britain and the West more broadly had interests around the world that were important in their own right, as well as having a potential connection to the cold war. Indeed, with a deliberate resort to war by the USSR being viewed as unlikely, preventing the outbreak of minor conflicts that could escalate became an important element of avoiding war. The Suez crisis both demonstrated the need for military intervention overseas and also shed a harsh light on existing British capabilities for such operations.
The second question concerned how such intervention should be conducted. Britain had hitherto relied on garrisons stationed overseas and on the use of air bases. These were expensive to maintain and as pillars of a strategy for intervention, they were being increasingly shaken by nationalism and decolonisation, resulting in the loss of bases or tight restrictions on their use. A potential ‘air barrier’ across the Middle East further complicated the British response to any crisis in the Gulf, Indian Ocean or Far East, reducing the utility of any UK-based strategic reserve. In response to these developments, the Admiralty was beginning to propose that the Royal Navy could take the lead ‘east of Suez’ with maritime task forces, based around carrier air power and amphibious capabilities, which would provide a stabilizing influence and a capacity for intervention. This vision appealed to those wanting a cheaper strategy as well as accommodating the reality of reducing access to overseas bases. It suited the Air Ministry which, focused on nuclear-armed bombers, was entirely content to see conventional, expeditionary air power fall primarily to the Fleet Air Arm. It also gave the Royal Navy a clear and viable role which attracted wider political support – at the same time as preserving capabilities that the Admiralty continued to see as essential for total war; hot war was de-emphasised in favour of warm and cold war.
The U.S. military greatly downsized after WW2 too. No more draft either. It was thought the next war would be nuclear and over in a few days if that. No need for large conventional forces. Korea proved that to be all wrong.
Well, the Admiralty, if it learned anything it quickly forgot it. Just look at the ships in the Falklands war, not was one able to defend itself against a pair (or two pairs) of Argentine A-4 Skyhawks at low level.
Just look at the AA guns the British did have, a useless 4.5″ gun, while missiles were unreliable or obsolete.
Now compare that to the Soviet, Italian, or even French ship of the 1980s.